Database design is the process of specifying the logical and/or physical parts of a database. The goal of database design is to make a representation of some "universe of discourse" - the types of facts, business rules and other requirements that the database is intended to model.

learn more… | top users | synonyms (2)

3
votes
0answers
76 views

Storing and querying rolling data in PostgreSQL

I have a large quantity of weather model data being put into a PostgreSQL database. The machine has 8 cores and 16 GB of RAM. I'm running PostgreSQL 9.3 with PostGIS 2.1. Each table will have a ...
3
votes
0answers
168 views

Mathematical method for spotting irregularity in numbers flow

I am trying to build an engine which is going to predict orders for items inside shop. Three main variables are: Time-dates (x-axe etc 1.1.2013,1.2.2013 etc I do calculation one per day) Available ...
3
votes
0answers
80 views

Replicating databases for local and cloud instances

Forgive me if this is an inappropriate place for this architectural question but I'm not sure where it best fits in the StackExchange family. I have been tasked with developing an online/live auction ...
3
votes
0answers
142 views

Database describing databases and references to tables

Context The company I work for makes a number of different softwares each with its own database. As they're all about related things (accounting) a good amount of data is theoretically the same among ...
3
votes
0answers
268 views

How to design a database for financial bond prices?

I have following flat file table composed of bond deal names and asociated prices. Each deal name is identified by its unique CUSIP and ISIN codes and each deal name is classified with a certain ...
2
votes
0answers
13 views

Should I use SQL Azure to store product descriptions and links to images in Azure Blob

For an html/Css/JQuery public Azure website to be coded using Zurb Foundation html5 responsive framework, I'd like to use SQL Azure (web edition) to store product descriptions and links to images that ...
2
votes
0answers
51 views

How to model (a many to many) to many relationship

Hello i am facing the following scenario. I have a student table with the following structure. Student id(PK), matriculation number, first_name, last_name, email A student can have more than one ...
2
votes
0answers
101 views

Problem with Database for survey Questionnaires

Bellow I am showing a sample survey question for woman. I need your help to creating a Database. Description: Top part of the survey Questions are Project Code, Name... etc which is ...
2
votes
0answers
123 views

Geographic Hierarchies in a OLAP Cube / Data Warehouse

Are the following geographic hierarchies correct? Do any US/Canadian area codes cross state/province lines? Do any US/Canadian counties cross state/province lines? Are there countries with counties ...
2
votes
0answers
88 views

Two different ON DELETE paths, how do I need to change the schema?

For a project in school I'm designing a website that sells items via auctions. Think eBay, but on the complexity scale of school project. We went through the process of making an ER Diagram and ...
2
votes
0answers
263 views

How to properly configure pgBouncer transaction level pooling?

What is a good way to determine the number of available transaction connections when using pgBouncer to pool database connections? Also, how should I determine the number of max_connections and ...
2
votes
0answers
95 views

Digital asset management

I'm working in a company that currently develops Media Asset Management system and now we want to improve our system for document files. I have to search nearly thousand .doc and .pdf files and index ...
2
votes
0answers
1k views

Schema for an RBAC (Role-based Access Control System)

I want to implement an RBAC, Flat based. I've decided to base my system on the NIST standardization model. Although all fine and well, I have an inclusion to that design. Instead of a hierarchy ...
1
vote
0answers
51 views

How to design a database structure for different groups of contacts?

I've been looking around for a while how systems manage their contacts. Most I encounter is creating a people or party table including a type to define the type of people/party. These types are either ...
1
vote
0answers
21 views

Basic Design Question about one to many in a table

Sorry for the basic question but I am new to all of this! Say I have a table named Runs, and each table has Run: id (primary_key) data (String - path to a data file) status timestamp ... ...
1
vote
0answers
26 views

Second opinion about elimination of possible redundant database column

We currently have a Widgets database table were we track the widgets the company produces. When a widget is produced the widget information is added to this table. This Widgets table contains a Status ...
1
vote
0answers
20 views

A better model for connecting users to different objects, even efter they cease to exist

I've got the privilege to create a small in-house application for managing todo-lists, although I am not really a developer. (I know some PHP and SQL, and got a chance to prove myself). As my ...
1
vote
0answers
107 views

Can somebody check this normalisation workings i think i am missing a step or a dependency somewhere

given these two tables: and: I need to first list them as an un-normalised structure(s) then i need to identify the functional dependencies/primary keys. Once i have done this i must represent ...
1
vote
0answers
30 views

How to join the tables in mysql to get wall messages and comments with name of person ? Only user and his friends messages

I have four tables in my mysql database as shown in the image url provided. I want to select data from the tables without duplication. I want to show messages and comments on wall according to the ...
1
vote
0answers
30 views

Keys of a relation

I got relation: R = { (ABCDEF) , (A B F -> C, B C -> F, F -> A, F -> B, D E -> E, E -> D)} keys of this relation are: {BCE}, {EF} But i dont get it... why? Why not only {EF}.. it got less ...
1
vote
0answers
108 views

SQLite Design: Better to have many tables with few columns or few tables with many columns?

I am struggling to figure out the best design for a Sqlite database that will hold data about Facebook pages so that I can calculate benchmarks for how the average Facebook page performs. I have an ...
1
vote
0answers
60 views

Relation between lossy decomposition and Natural join?

I am confused with the lossy decomposition and natural join. Natural join(with common attribute): only respective common attribute for the resultant table is formed. Lossy: Natural join on tables ...
1
vote
0answers
39 views

Schema for yearly data models

I am developing a school management system. Most data will not be reused after the end of the school year. I am contemplating using schemas to separate data in various school years, however I am ...
1
vote
0answers
57 views

MySQL: What criteria should I base my table column order/arrangement/grouping on?

Does the order, arrangement or grouping of columns with large (such as long text descriptions) and small (such as bit and tinyint) field types have any noticeable impact on MySQL (InnoDB engine) ...
1
vote
0answers
25 views

Optionally free-form reference

I've seen a few instances of entities which have a field which can be either a reference to another entity or free text. You typically represent this in the UI by having a dropdown widget which can ...
1
vote
0answers
61 views

The correct way of representing folders

I'm trying to kind of emulate a folder structure in my application. Now I've thought of two ways to achieve this, but what is the best practice for that? Table: Attachments Columns: Id (PK), ...
1
vote
0answers
39 views

Is it always bad to have an own table for value objects?

I know that value objects should be embedded in the table of the object they belong to but what if the value object is more than a simple object and contains many fields/columns or even sub-objects? ...
1
vote
0answers
75 views

How to store object with property of generic type in DB

In my business domain there exists an entity parameter. Beside other properties which are identical for each parameter, they have values. These values can be of different data types. There might be ...
1
vote
0answers
99 views

Are duplicates ever acceptable in a database

A warehouse system I am working on allows inwards consignments [type = 0] and outwards consignments [type = 1]. The user selects multiple products for each consignment and then multiple warehouse ...
1
vote
0answers
47 views

Where should a default setting field be?

I am creating a database to track occurrences of incidents on buses based on an existing system. Currently the drivers can set a default bus number, which is used to pre-populate the bus number on the ...
1
vote
0answers
417 views

which role-permission database design?

I want to manage roles and permissions. Most of designs on web look like this tables: Users Roles UserRoles Permissions RolePermissions Here, what is permissions? I am thinking for such a design ...
1
vote
0answers
155 views

Data modelling: RBAC for small enterprise software

I'm building the core tables for a small, cloud-based enterprise app. Is this data model suitable for a role based authentication system (flat hierarchy of permissions) that allows users to work for ...
1
vote
0answers
129 views

Database Design: separating reusable & instance data

I'm developing an app which is basically a collection of checklists that have to be processed. I obviously need a database in which the information has to be stored. I just can't wrap my head around ...
1
vote
0answers
103 views

Real Time data collection - Help select Database

My Scenario: I want to collect data from various sensors[for now I have 600 sensors sending data, but this may have to scale up to 3000 more data sensors, all sensors send real time data] Now I have ...
1
vote
0answers
342 views

How to represent class table inheritance (current DBMS-specific way please)?

I want to implement class either-or table inheritance (Account, CatAccountDetails, DogAccountDetails) in SQL Server. I found a recommendation for MySQL here (How do I map an IS-A relationship into a ...
1
vote
0answers
78 views

Unable to decompose this relation to BCNF

I have a relation R = { A, B, C, D, E, F, G, H, I } And functional dependencies F ={ ABC -> DE E -> C AB -> F C -> G F -> H H -> IJ F -> B } I am able to do simple BCNF ...
1
vote
0answers
217 views

PeopleSoft or Oracle App Designer Tool Alternative

We are using PeopleSoft app designer tool to manage and create projects, database objects - tables, columns, views etc in Oracle database. This tool has limitation that we cannot create tables/columns ...
1
vote
0answers
95 views

key value database

I have one object and a lot of data associated with that object, you can think of it as something like facebook timeline where we have user and user has a lot of posts. I cannot store data in JSON ...
1
vote
0answers
182 views

Improving database design for category based site

I'm working on a site that gets about 30k visits a day and it makes use of a lot of queries which uses UNION's over about 45 different tables, these tables generally range from about 15k rows to about ...
1
vote
0answers
266 views

How do I auto-fill data in Microsoft Access 2003?

I am creating a Purchase Order Form at work using Microsoft Access 2003 so that it can be saved and archived in a database and reduce paper costs. These are my current dilemmas: I am unable to ...
0
votes
0answers
7 views

How much the decision to use ternary or binary relationship influences the accuracy of the model with regards to a given business model?

The question title is very long, so here's a little bit of context to (try to) make it clear. I asked a question regarding ternary relatinship. The question was Ternary relationship: what's the ...
0
votes
0answers
17 views

Conversion of simple ERD to Table: is the solution below any good?

Consider the following ERD: Suppose that all entities only have two attributes: a PK plus a name/number. I want to convert that ERD to tables. Is it needed 4 tables (1 for each relationship ...
0
votes
0answers
4 views

MySQL Workbench EER Diagram and ENUM data type

I am creating EER model diagram using MySQL Workbench (version : 5.2.47) The version for MySQL, I am using is 5.5.35-0ubuntu0.13.10.2. I have created a schema with 'Default Collation' set to 'utf8 - ...
0
votes
0answers
24 views

Database structure for maintenance planning

I'm currently working on a solid way of creating a sort of planning system. In this system, I need an productgroup to be made (= category name for a list of items, like cars) with producttype as ...
0
votes
0answers
14 views

using the wordpress approach for storing taxonomies

multiple tables vs single table a user table will not need every social link in the database column, since every one will not enter all their social links and are used only on user profile ...
0
votes
0answers
30 views

How to convert this relation to 2NF?

In my Entity Relationship Diagram, an entity type TEACHER had a relationship of TEACH with another entity type called CLASS. CLASS was a week entity type of TEACHER,so when mapping to a Relational ...
0
votes
0answers
20 views

Organizing a couple tables in postgresql

I have a data structure that is represented like this: { 'question_id': 1, 'is_required': False, 'question_text': [ { 'id': 1, ...
0
votes
0answers
44 views

Database Design for NoSQL Fantasy Baseball League

I am trying to create a proper schema to place scraped data into, using a MongoDB database. Currently it looks like Team { id : id, name : String, teamLink : String, username : ...
0
votes
0answers
15 views

Problem in altering PK columns with macro

In Embarcadero ER Studio Data Architect (version 9.5), I have a problem in a macro i am realizing to import the contents of two excel files. Basically one of them contains informations about ...
0
votes
0answers
41 views

Reduce read write delays in specific database setup

I have a database with a large table with 15 columns (type double). It contains a large amount of data (~ 100 rows of data for every second. Holds 3 days of data). I also have a real-time program that ...